1. Field of the Invention
The present invention relates to a tunneling field effect transistor (TFET) and fabrication method thereof, and more particularly to a TFET having interfacial layer containing nitrogen and fabrication method thereof.
2. Description of the Prior Art
In the past decades, semiconductor integrated circuit (IC) industry has developed rapidly. The advancement of semiconductor materials and manufacturing technology allows ICs to contentiously shrink with increased complexity and improved performance. More semiconductor devices having smaller feature sizes may be formed within a unit area of a semiconductor substrate to achieve a higher integrity. However, it adversely results in some technological problems. For example, closely arranged semiconductors devices may have larger leakage current and obvious signal interference. Furthermore, power consumption is also a primary concern in advanced technology.
Tunneling field effect transistors (TFETs) have been proposed to take the place of conventional metal-oxide semiconductor field effect transistors (MOSFETs) in some applications confronted with the aforesaid problems. TFETs are advantageous over conventional MOSFETs in the respects of smaller sub-threshold swing (for example, smaller than 60 mV/dec), larger on-off current ratio (Ion/Ioff) and smaller off-state leakage current (Ioff).
However, there are still some problems in existing TFETs. For example, the on-state current (Ion) of a TFET is too low for certain application and the sub-threshold swing of a TFET still need further improvement.